Combustible mixture and process for preparing the same



Patented June 24, 1930 UNITED STATES PATENT, err] JULIUS THIECKE, OFBERLIN, GERMANY, ASSIGNO'R'TO MINIMAX 1. 6%., A'CORPORA- TION OFGERMANY, AND DEUTCl-ISE PYROTEG HNISGHE EA'BBIKEN' 'A.-G., A GOR-IORATION OF GERMANY, BOTH OF BERLIN, GERMANY COMBUSTIBLE MIXTURE ANDPROCESS FOR PREPARING"T-HE1$AM E-- No Drawing. Application filedDecember 20, 1928, Serial No. 327,462, and in German October 25, 1927.

My invention relates to improvements in combustible mixtures forgenerating heat, compressed gas or choke gas, and to a process forpreparing the same. My improved combustible mixture consistssubstantially of animal charcoal and ammonium nitrate 'a suitableproportion. In a preferred process 15 parts by weight or" animalcharcoal are mixed with 85 parts by weight 01": ammonium nitrate andpressed into solid bodies or cartridges to facilitate handling andapplication of the product. Since ammonium nitrate is hygroscopic it isnecessary to exclude the air by an envelope and to prevent the admission of dampness. The envelope or wrapping may be combustible, but itmay equally well consist of a refractory material and then form acombustion chamber, whereby the heat may more easily be concentrated ona certain point.

The mixture has various advantages. Above all it burns Without any airbeing admitted, so that it is perfectly utilized in closed chambers andleaves no appreciable residue behind. In comparison with other mixtures,primarily gunpowder, it burns very slowly and produces a uniformlyrising pressure. This may be accounted for by the fact, that thecombustion is not substantially accelerated even when the pressurerises. The comparatively low combustion temperature probably'has aninfluence in this direction. The containers for the compressed gas mayconsequently be accurately calculated and the danger of an ex plosion beavoided. To these must be added the further advantage, that the mixturemay easily be ignited, for instance by a small priming set, the openflame, an incandescent wire or an electric spark.

When using the mixture of ammonium nitrate and animal charcoal forgenerating compressed gas, it is burned in a closed chamber, which isput in communication with the place of consumption in any de sired knownmanner. Since the combustion does not require a supply of air and sincethe increase of pressure during the combustion is only small, thecombustion chamber may be made comparatively small.

small quantities of smoke, steam and vapor,

my improved compound may also be used in a partly closed receptacle evenin storage rooms for inflammable substances. For the development ofchoke gas or nitrogen for suppressing fires in the holds of ships orother closed rooms or for killing vermin the fact that the mixture burnswithout a flame is likewise of great advantage, while its low combustiontemperature does not let the mixture appear as easily inflammablesubstance.

Ammonium nitrate has already been suggested or used as addition toblasting substances and black gunpowder. The remaining constituentsincreased, however, the velocity of combustion of the mixture up to anexplosion, so that such mixtures were unsuitable for generatingcompressed gas in closed containers. I have found by extensiveexperiments, that animal charcoal mixed with ammonium nitrate results ina compound, which has special qualities for many purposes, and isparticularly valuable for the use by the public, inasmuch as its speedof combustion does not increase substantially when the pressure rises.The two constituents of the mixture, animal charcoal and ammoniumnitrate, are essential for the favorable qualities of the mixture. Thespeed of combustion may, however, be varied in a difierent degree byadding other kinds of carbon, such as ordinary charcoal, whereby thecombustion is retarded.

The compressed gas may be employed for various purposes, for instancefor forcing liquids out of closed containers, as in the case of fireextinguishers, paint or cement guns, siphons, atomizers, as well asdriving medium for pneumatic tools, air brakes, ejectors and forstarting gas motors.

I claim as my invention 1. The process of preparing a combustiblecompound for generating compressed gas, choke gas or heat, whichconsists in mixing

